New Delhi: Police in northern India will soon use slingshots loaded with chilli powder and marbles to tackle unruly protesters in the world's largest democracy, an inspector said on Wednesday.

Not content with water cannon, tear gas and traditional wooden sticks or lathis, police in Haryana state close to New Delhi will turn to the slingshots as a "non-lethal way" to control violent crowds.

Representational image. AFP

"Plus it is much better than firing plastic bullets which can cause pretty bad injuries," police inspector general of Hisar district, Anil Kumar Rao, told AFP.

"It will be used only in emergency cases so that we can manage minimum collateral damage," added Rao, who came up with the idea.

The locally-made slingshots are the latest in a series of unconventional measures adopted by security forces in India, which sees daily protests on a myriad of issues. Some quickly escalate out of control.

In April 2015, police in the northern city of Lucknow said they were introducing pepper-spraying drones to control "mob crowds".

Critics say the marbles could cause serious injury, but Rao said they would be used sparingly and only after the "chilli balls" failed.

"And it's not like we plan to use marbles on peaceful protesters, it's only meant to control hostile people," said Rao, whose officers have started practising with the slingshots.

"We have to step in and take certain action when people are burning government property, cars. This is a very, very positive step – a civilised, cost-effective weapon."